Machine for finishing concrete surfaces

ABSTRACT

A machine for smoothing the surface of newly poured concrete including a float which is moved across the concrete surface by a carriage traveling back and forth on an overhead frame spanning the surface. The float is vertically self-adjusting and reciprocates lengthwise as it moves across the concrete surface. The machine also includes a tilt adjustment, pressure adjustment and skew adjustment for the float and means for lifting and lowering the float to the concrete surface.

United States Patent Inventor John A. Borges 601 Duane Avenue, OregonCity, Oreg. 97045 Appl. No 782,147

Filed Dec. 9, I968 Patented Sept. 14, I971 MACHINE FOR FINISHINGCONCRETE SURFACES 14 Claims, I0 Drawing Figs.

[52] US. Cl.... 94/45 [5|] Int. Cl EOIc 19/22 {50] Field of Search 94/45{56] References Cited UNITED STATES PATENTS 2,650,525 1/1953 Jones 94/452,957,396 10/1960 Bederman 94/45 $094,048 6/ I 963 Hudis 94/45 3,208,3619/ I 965 Bidwell 94/45 3,368,466 2/1968 Rowe 94/45 3,452,654 7/1969Kessel 94/45 Primary Examiner-Jacob L. Nackenoff A!t0rneyBuckh0rn,Blore, Klarquist and Sparkman ABSTRACT: A machine for smoothing thesurface of newly poured concrete including a float which is moved acrossthe concrete surface by a carriage traveling back and forth on anoverhead frame spanning the surface. The float is verticallyself-adjusting and reciprocates lengthwise as it moves across theconcrete surface. The machine alsoincludes a tilt adjustment, pressureadjustment and skew adjustment for the float and means for lifting andlowering the float to the concrete surface.

PATENTEU SEP] 4 |97| SHEET 1 BF 3 JOHN A. BORGES INVENTOR BUB/(HORN,BLORE, KLAROU/ST a SPAR/(MAN ATTORNEYS PATENTEUSEPWBH 3.604.325

SHEET 3 OF 3 JOHN A. BORGES /N 1 5 N T 0/? B) BUCKHOHW, BLORE, KLAROU/ST 8 SPAR/(MAN ATTORNEYS MACHINE FOR FINISHING CONCRETE SURFACESBACKGROUND OF THE INVENTION I. Field of the Invention The presentinvention relates to a machine for smoothing and compacting the surfaceof concrete bridge decks, roadways and other slabs.

2. Description of the Prior Art The manual float method of smoothing thesurface of newly poured concrete has been used for many years. Itspurpose is to smooth and compact the concrete surface to preventchecking and to provide the slab with a smooth, even surface aftershrinkage. The concrete surface is smoothed according to the floatmethod after the slab has been rodded off to grade and contour and afterthe newly poured concrete has taken an initial set.

Heretofore the float method of smoothing concrete has been a handoperation using a straight wooden plank with plow handles attached toits opposite ends. According to this method, the slab must be spannedwith two longitudinally spaced foot walks suspended above the slab andspaced or 12 feet apart. Two men, one on each foot walk and at each endof the plank, drag the plank across the slab, see-sawing the float plankas they move it across the slab. Additional help is often required topull the heavy float plank with ropes across the slab.

The foregoing method gives good results only if the operation isperformed by experienced, skilled persons at the proper time. Moreover,the time and effort required in moving the foot walks along the slab andin pulling the heavy, cumbersome float plank limits the use of the handmethod to small pours of concrete. Nevertheless, highway bridgespecifications of several states require that this type of float finishbe used to attain small surface tolerances of, for example, one-eighthinch in 10 feet.

Machines have been suggested for smoothing the surface of concrete, butsuch prior machines have not been capable of duplicating or approachingthe smooth and compact surface obtained using the above-described manualfloat finishing method.

SUMMARY OF THE INVENTION The present invention provides a machine forapplying a smooth float finish to the surface of concrete of a qualityformerly obtained only by persons highly skilled in using manuallyoperated wooden floats. The machine powers a long wooden float across aconcrete surface to be finished while simultaneously reciprocating thefloat in a direction lengthwise of the float and while the float adjustsitself automatically to the contour and grade of the surface. Themachine itself is powered for movement along the slab to be finished.Float tilting means are provided for changing the angle of attack of thefloat with respect to the concrete surface, and additional means areprovided for skewing the float with respect to its direction of travel.A single operator controls the finishing operation, including the tiltof the float, and raising and lowering of the float with respect to thesurface of the concrete, and the float travel from an operator'splatform on an overhead carriage from which the float is suspended. Themachine enables the smoothing operation to be carried out by one person,in a minimum time and with minumum effort, making practical theapplication of the float finishing method to large surface areas whichheretofore could not be float finished practically by hand.

BRIEF DESCRIPTION OF THE DRAWING The foregoing features and advantagesof the present invention will become more apparent from the followingdetailed description which proceeds with reference to the accompanyingdrawings wherein:

FIG. 1 is a foreshortened side elevation of an apparatus in accordancewith the present invention;

FIG. 2 is an end elevation of the apparatus of FIG. I taken along theline 2-2 of FIG. I, on an enlarged scalc and foreshortened in width;

FIG. 3 is a vertical sectional view taken approximately along the line33 of FIG. I on a scale slightly reduced from that of FIG. 2;

FIG. 4 is a vertical sectional view taken approximately along the line4-4 of FIG. 3 on thesame scale as FIG. 3;

FIG. 5 is a vertical sectional view taken along the line 55 of FIG. 4 onthe same scale as FIG. 4;

FIG. 6 is a vertical sectional view taken along the line 66 of FIG. 4 ona scale enlarged from that of FIG. 4;

FIG. 7 is an enlarged elevational view, partly in section, of the lowerfloat assembly portion of the apparatus shown in FIG. 3;

FIG. 8 is a vertical sectional view taken along the line 8-8 of FIG. 7on the same scale as FIG. 7;

FIG. 9 is a horizontal sectional view taken along the line 9- I DETAILEDDESCRIPTION General Assembly With reference to the drawings, FIG. 1discloses the apparatus of the invention including a generallyrectangular overhead frame structure 10 which spans the width of asection of newly poured concrete, bridge deck, highway pavement, orother slab 12, the surface of which is to be finished. The framestructure includes a pair of longitudinal side frame members 14 and endframe members 16 (FIG. 2) supported at each of its four corners by legs17 on grooved wheels 18 which travel on a pair of tubular tracks 20 laidalongside the opposite sides of the slab. As shown best in FIGS. 2 and3, side frame members 14 have inverted angle members affixed to theirupper surfaces to define a pair of tracks 22 on which wheels 24 of acarriage 26 are guided as the carriage travels back and forth along theframe over the slab to be finished.

A long, straight, rectangular float member 28 rests of its own weight onthe surface of the slab l2 and is dragged across the slab surface duringmovement of carriage 26 back and forth on overhead frame 10 to compactand smooth such surface. The float member is mounted for self-adjustingvertical movement and for see-sawing movement lengthwise of the float asit moves across the slab surface by a float mounting means 30 suspendedby a pair of vertical hangers 32 from the carnage.

Float Assembly and Mounting Referring particularly to FIGS. 3, 7 and 8,the float member includes a long, straight wooden plank 34 having one ofits flat broad surfaces in contact with and normally resting upon thesurface of the slab 12 to be finished. The plank may extend for a lengthof 10 feet or more and has an upright metal channel member 36 bolted tothe upper surface of the plank along its longitudinal centerline. Thechannel itself is capable of receiving metal weights whereby a variablepressure can be applied to the concrete surface by the float. The floatmounting means 30 includes vertical slide means which permits the floatplank to adjust itself vertically to the surface grade and contour ofthe concrete as it rides over the surface. Such slide means includes apair of vertical slide rods 38 connected at their lower ends at 39 tothe opposite ends of float channel 36 and a pair of vertical sleeves 40carried by the mounting means 30 for slidably receiving slide rods 38.From FIG. 8 it will be evident that with this arrangement float mount 30can travel in a straight horizontal path as induced by the carriagewhile the float follows an independent path determined by the grade andcontour of the slab surface.

Referring to FIGS. 8 and 9, each guide sleeve 40 is fixed, as bywelding, to an enlarged end 41 of a threaded bolt 42 which extendsthrough a horizontal pipe section 43 and is secured at its opposite endby a nut 44 which abuts an enlarged end 45 of pipe 43 to apply anadjustable tension to the bolt. In this manner guide sleeve 40 and thusthe float structure can be provided with a certain lengthwiseflexibility during reciprocation of the float to prevent damage to thefloat mounting and drive means. Each horizontal pipe section 43 is fixedto one of a pair of rectangular horizontally slidable members 47 mountedfor sliding movement along an elongated guideway 48 of rectangular crosssection.

Stub shafts 50 projecting from the opposite ends of guideway 48 extendthrough opposite end channel members 52, which, together with a pair ofside channel members 54, define a rectangular box frame portion of themounting means. Guideway 48 is secured to end members 52 of the boxframe by nuts 56 threaded onto stub shafts 50. Stub shafts 50 alsoproject through openings in the lower ends of the hanger members 32 andare limited in their longitudinal sliding movement by collars 58, 59secured to stub shafts 50 on opposite sides of each hanger 32. Thisenables the entire mounting assembly 30, including the box frame and itssupported guideway, slides, float guide means and float, to pivottogether about the axes of stub shafts 50 from hangers 32.

The box frame of the mounting assembly 30 also supports a pair of anglemembers 61, 62 as shown in FIGS. 7 and 8, which together serve as a baseto which a speed reduction unit 64 of an electric motor 66 is fastenedto support both the speed reducer and the motor. Motor 66 drives a crankwheel 68 through the speed reduction unit, and the crank in turn isconnected by a connecting rod 70 to one of sleeves 47 to translaterotary motion of the crank disc to reciprocating movement of theconnected slide 47 along guideway 48. The driven slide 47 is in turnconnnected by a tie rod 72 to the other slide 47 whereby both slidesreciprocate in unison thereby inducing a see-sawing motion on the floatas it is moved across the slab by the carriage.

Float Tilt and Lift Means As previously indicated, the entire mountingassembly 30 is mounted for pivotal movement on stub shafts 50 relativeto hangers 32 to enable tilting of the float plank 34 horizontally in afore-and-aft direction to change the angle of attack of the float plankwith respect to the surface of slab 12. The means provided for tiltingthe mounting assembly includes a long vertical rod 76 shown most clearlyin FIGS. 1, 3 and fixed at its lower end to one of side channels 54 ofthe box frame. Stub shafts 50 are offset on one side of the longitudinalcenterline of the box frame, as clearly shown in FIG. 8, and rod 76 isoffset on the opposite side of such centerline, thereby increasing theleverage effect of rod 76 and thus the ease of tilting the floatassembly about the pivot axis of the assembly.

Rod 76 extends upwardly to an upper terminus above carriage 26. Ahorizontally disposed handlebar 78 is pivoted nearer one end than theother to the upper end of rod 76. The other end of the handlebar isconnected by a tie rod 82 to the outer end of a horizontally extendingbar 80 pivoted to rod 76 below the handlebar. Bar 80 is notched atintervals along its lower edge for selective locking engagement with anupwardly extending licking member 84 fixed to one of hangers 32 on thecarriage. When notched bar 80 is lifted by handlebar 78 out of lockingengagement with bar 84, the upper end of rod 76 can be moved easilyhorizontally, which in turn effects a pivoting movement of the floatmounting assembly about the pivot axes of stub shafts 50 to change theangle of tilt of the float with respect to the concrete surface. Whenthe desired tilt is achieved, the notched bar 80 is dropped onto lockingbar 84 by pivoting the long end of handle 78 downwardly, thereby lockingrod 76 and thus the float plank in their adjusted positions.

Means are also provided for lifting and lowering the float plank intocontact with the surface of the concrete slab, as shown in FIG. 3.. Suchmeans includes an upstanding frame structure 86 on a platform portion 88of carriage assembly 26 and a hand-operated winch 90 mounted at operatorheight at the upper end of frame 86. A cable 92 on the winch drum (notshown) extends downwardly through the carriage assembly to a connection93 with a pair of branch cables 94, 95, which diverge downwardly fromconnection 93 to connections 96, 97 with channel portion 36 of floatmember 28. By passing out or taking in cable 92 with winch 90, floatplank 34 can be lowered to or lifted from contact with the slab surface.A spring 99 extends between main cable 92 and an arm on the frame totake up slack in the cables when the float is resting on the slab.

Carriage Assembly Carriage 26 includes an open rectangular base 98formed of four channel members as shown in FIGS. 4 and 5. The basemounts axle members 100 which rotatably mount carriage wheels 24. Theupper side of base 98 supports an annular turntable 102 having achannel-shaped cross section. Circular platform 88 is positioned withinannular turntable 102 and is mounted in a manner whereby the platformremains stationary while the turntable may be rotated within limits. Tothis end turntable 102 includes a series of four brace bars 104 whichradiate from the center of the space within the turntable to the innerperiphery thereof where they are secured to annular channel 102. Thebrace bars are held together at the center of the turntable by an upperbearing plate 106. Brace bars 104 lie just beneath platform 88 andrestrain the platform against any appreciable tilting movement.

A lower bearing plate 108 in face-to-face engagement with upper plate106 is fixed to a pair of parallel and horizontally spaced angle members110, 111 which extend the width of base 98 and are secured at theiropposite ends to the side channels of the base. Thus the platformis-supported through the bearing plates and angle members by base 98. Astop bar 112 extends downwardly from the underside of platform 88between angle members 110, 111 of the base to prevent movement of theplatform 88 when turntable 102 is rotated. A kingpin 114 extendsdownwardly through an opening in platform 88, between brace bars 104,through bearing plates 106, 108, and between angle members 110, 111. Thekingpin has a nut 116 threaded on its lower end which tensions the pinwhen screwed against washers 1 18 and a large abutment plate 120 fixedto the two angle members 110, 111. The nut has a pair of handle rods asshown in FIG. 4 to facilitate its loosening and tightening by hand.

When the kingpin is placed in tension by tightening nut 116, turntable102 cannot be rotated. When the nut is loosened, the turntable can berotated about the kingpin, while at the same time stop 112 preventsrotation of platform 88. As shown in FIG. 5, the upper ends of floathangers 32 are fixed to the rotatable turntable 102. Thus, by rotatingthe turntable slightly the entire float mounting assembly and the floatcan be oriented on a skew with respect to the direction of travel of thefloat and carriage across slab 12.

Platform 88 mounts not only frame 86 for the float lifting winch 90 butalso a reversible electric motor 122 for powering the carriage back andforth on frame 10 across the slab. Electric motor 122 may beautomatically reversed via limit switches (not shown), or its reversingaction may be manually controlled by a control 124 mounted on winchstand 86. The carriage motor includes a pulley wheel 126 about which onewrap of a horizontally extending cable 128 is trained. As shown in FIG.1, cable 128 is anchored at one end of frame 10 on a post 130, and iswound on the drum of a post-mounted hand winch 132 at the oppositeend ofthe frame to enable adjustment of the tension in the cable. Uponrotation of pulley 126 the carriage is pulled along cable 128.

Electric power for operating float motor 66 and carriage motor 122 issupplied from an external source such as, for example, agasoline-powered generator near the machine, and is conducted to thecarriage through a conductor cable 134 suspended from a support wire136. Wire 136 is supported by high posts at the opposite ends of frameas shown in FIG. 1. A cantilever beam 138 on winch stand 86 suspends aspring support 140 from its outer end, and the support in turn supportsa portion of support wire 136. Beam 138 also serves as a retainer andsupport for conductor cable 134 which may be wrapped about the beam asshown in FIG. 3 as it extends to control 124 and then to the motors.

Frame Adjustments Frame 10 itself contains several adjustments whichincrease the versatility of the machine. First, with reference to FIG.2, it will be noted that each leg 17 is telescoping and includes aninternal jack operated by a crank handle 142 at the top of the legwhereby the height of the overhead frame above the slab can be varied.Furthermore each leg 17 is rigidly affixed to one of the two box-shapedlongitudinal side frame members 14 by a U-bracket 144. Bracket 144 isheld in a preselected position along a side frame member by clamp bolts145. By loosening the bolts, each leg may be slid along its frame memberto any desired position to vary the effective length of the machine toaccommodate any width of slab up to the maximum length of thelongitudinal frame members. This same feature together with telescopinglower leg braces 146 at opposite ends of the frame enable thelongitudinal frame members l4 and thus the carriage and float to beoriented on a skew with respect to the side edges of slab 12 while atthe same time frame 10 is capable of travel lengthwise parallel to theslab. Setscrews 147 on the leg braces hold the leg braces at any desiredlength. The need for operating the frame on a skew is encountered incertain types of construction, such as on bridge approaches whichintersect the bridge deck at an angle.

One wheel 18 at each end of the frame is powered by a chain and sprocketdrive 149 from an electric motor 150 mounted on a platform 152 at thebase of a leg 17. An appropriate control panel (not shown) may bemounted on one end of the frame for controlling the operation of theframe wheel motors 150 whenever it is desired to move the frame alongthe slab.

Operation In operation pipe tracks 20 are laid parallel and close to theopposite side edges of a slab 12 to be finished, such as a bridge deckor roadway. The frame is then set up for movement along the trackintermittently by operation of wheel motors 150. The width of a sectionof slab that may be smoothed at one time is determined, of course, bythe length of the float plank itself. The surface of the slab is notsmoothed until after the slab has been poured, the fresh concrete hasbeen rodded off to grade and contour either by hand or by any one of anumber of finishing machines for this purpose, and after the freshlypoured concrete has taken its initial set. When this has occurred, thefloat is lowered into contact with a section of the slab surface to befinished, using hand winch 90, and the float is allowed to rest on thesurface under its full weight, which may be varied by securing weightsto the float channel 36.

The carriage motor 122 and float reciprocating motor 66 are energized bythe operator standing on platform 88. Carriage 26 moves back and forthon frame 10, moving float 28 with it across the surface of the concretein a see-sawing motion. However, the control of the carriage and floatmotors is such that either motor can be operated independently of theother so that the float can be moved across the slab without asee-sawing motion if desired, or so that the float can be reciprocatedlengthwise at one spot on the concrete while the carriage remainsstationary. The pin and sleeve mount of the float enables it to conformto the general contour and grade of the concrete surface as it travelsacross the surface with its see-sawing motion.

The carriage travels back and forth across the same section of slab asmany times as may be necessary to lay down and remove all high placesand fill all low spots in the surface.

When the desired surface finish of one section of the slab has beenobtained, the float is lifted from the surface using cable winch 90, thecarriage and float motors are stopped, and the frame is movedlongitudinally of the slab approximately'onehalf the length of thefloat. Thus, for example, if the float will smooth a 10-foot swath inone position ofthe frame, the frame is moved longitudinally at 5-footintervals. When the frame has been moved, the entire operation isrepeated, and then the frame is moved at subsequent intervals until theentire surface of the slab has been smoothed.

A single man can handle the entire operation with ease while riding theplatform of the carriage. From the carriage, the operator has completecontrol of the operation of the carriage and float motors, float tiltand float lift.

Having illustrated and described apreferred form of the invention, itshould be apparent to those having skill in the art that the samepermits of modification in arrangement and detail. I claim as myinvention all such modifications as come within the true spirit andscope of the following claims.

1. ln an apparatus for finishing a concrete surface including anoverhead frame structure spanning the width of said surface and movablelengthwise thereof, and a carriage movable on said frame structureacross said surface,

a float structure for smoothing the concrete surface comprising:

a float member adapted to engage the concrete surface,

float-mounting means positioned above said float member and mountingsaid float member so as to be self-supporting on said surface, saidmounting means including vertical slide means interconnecting saidmounting means and said float member so as to permit self-adjustingvertical movement of said float member as determined by the contour andgrade of said surface while controlling horizontal movements of saidmember, said vertical slide means including vertically extending sliderod means and guide sleeve means slidingly receiving said rod means, oneof said sleeve and rod means being connected to said float member andthe other being connected to said mounting means, said mounting meansincluding horizontally slidable means mounting said vertical slide meansfor horizontal reciprocation in a direction lengthwise of said floatmember,

float-reciprocating means carried by said mounting means forreciprocating said horizontally slidable means and thus said verticalslide means and said float member generally horizontally,

and means suspending said mounting means from said carriage wherebytravel of said carriage on said frame moves said float member across theconcrete surface during reciprocating and self-adjusting verticalmovement of said float member.

2. Apparatus according to claim 1 wherein said float member comprises anelongate flat straight member having leading and trailing edges asdetermined by the direction of travel of said carriage,

said reciprocating means reciprocates said member lengthwise,

said means suspending said mounting means including means mounting saidmounting means for pivoting movement about a horizontal axis of saidmounting means extending lengthwise of said float member,

and vertically movable means on said carriage and pivotally connected tosaid mounting means at a position offset from said horizontal axis fortilting said mounting means and thus said float member about said axisso as to change the height relationship between said leading andtrailing edges.

3. Apparatus according to claim 1 including winch on said carriage meansfor raising said float member from the concrete surface and for loweringsaid float member into contact with said surface.

4. Apparatus according to claim 1 including vertically movable means onsaid carriage and connected to said mounting means for tilting saidmounting means and said float member about an axis extending generallyparallel to a leading edge of said float member and winch means on saidcarriage for lifting said float member from the surface of saidconcrete.

5. Apparatus according to claim 1 including skewing means forvarying theangular orientation of said float member with respect to said concretesurface in a generally horizontal plane whereby said float member can bemoved across said surface while skewed with respect to the direction oftravel of said carriage, said skewing means including turntable means onsaid carriage shiftable about a vertical axis, said means suspendingsaid mounting means being connected to said turntable means wherebyshifting of said turntable effects a skewing of said mounting means andthus said float member.

6. Apparatus according to claim 1 wherein said carriage included anoperator's platform, motor means carried by said platform, pulley wheelmeans driven by said motor means, and pulley cable means for moving saidcarriage along said frame, and control means mounted on said platformfor controlling the operation of said motor means and thus saidcarriage.

7. Apparatus according to claim 6 wherein said float member includes anelongate, straight member having a broad flat bottom surface, liftingmeans on said carriage and connected to said float member for liftingsaid float member from the concrete surface, tilt means on said carriageand connected to said mounting means for varying the angularrelationship of the bottom surface of said float member to the concretesurface to be finished, and tilt and lift control means accessible fromsaid platform for controlling said lifting means and said tilting means.

8. An apparatus for smoothing a concrete surface comprising:

an overhead frame structure for spanning the width of the concretesurface to be smoothed and supported on wheeled legs at its oppositeends for travel lengthwise of said surface,

a carriage movable on said overhead frame structure across said surface,

an elongate float member for smoothing the concrete surface,

and float-mounting means depending from said carriage mounting saidfloat member for self-adjusting vertical movement as determined byvariations in grade and contour of said surface and for horizontalreciprocating movement lengthwise of said float member,

said float-mounting means including a horizontally reciprocative memberslidable lengthwise of said float member, vertical guide sleeve meanscarried by said reciprocative member, and slide rod means extendingvertically from said float member and slidable within said guide sleevemeans.

9. Apparatus according to claim 8 wherein said legs supporting saidframe structure are extensible for adjusting the height of said framestructure above the surface to be smoothed.

10. Apparatus according to claim 8 including power means drivinglyconnected to at least one of said wheeled legs for driving said framestructure lengthwise of said surface.

11. Apparatus according to claim 8 including means for adjusting theposition of said legs along the length of said frame structure forvarying the effective length of said frame structure to accommodatevarying widths of concrete surfaces and to enable the skewing of saidoverhead frame structure with respect to the direction of travel of saidstructure.

12. Apparatus according to claim 1 wherein said slide means permittingvertical self-adjustment of said float member includes an upright sleevemember carried by a horizontally reciprocative portion of said mountingmeans and an upright slide member extending upwardly from said floatmember and slidable within said sleeve member.

13. Apparatus according to claim I wherein said means for reciprocatingsaid float member included a horizontal guide member, said horizontallyslidable means being mounted for slidin movement along said guidemember,

sai horizontally slidable means pivotally mounting said guide sleevemeans,

said slide rod means being pivotally connected to said float member andslidable within said vertical guide sleeve means,

motor means carried by said mounting means,

and float drive means drivingly connected to said horizontally slidablemeans and said motor means for reciprocating said horizontally slidablemeans back and forth on said guide member.

14. Apparatus according to claim 8 wherein said carriage comprises:

a wheeled base movable on said frame structure,

a turntable supported on said base for turning movement about a verticalcentral axis relative to said base,

and an operator platform supported by said base and restrained againstturning movement relative to said base,

and hanger means extending downwardly from said turntable supportingsaid float-mounting means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,604,325 Dated September 14 1971 Inventofls) JOHN BORGES It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 3, line 61, "licking" should be -locking; Column 5, line 29,"Setscrews" should be --Set screws--; Column 6, lines 70-71, claim 3,"including winch on said carriage means" should be -including winchmeans on said carriage; Column 7, line 16, claim 6, "included" should be--includes-; Column 8, line 25, claim 13, "included" should be--includes--.

Signed and sealed this 21st day of March 1972.

(SEAL) Atte'st:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents M 90-1050 (10-69) UsCOMM-DC aoa'rs-pn

1. In an apparatus for finishing a concrete surface including anoverhead frame structure spanning the width of said surface and movablelengthwise thereof, and a carriage movable on said frame structureacross said surface, a float structure for smoothing the concretesurface comprising: a float member adapted to engage the concretesurface, float-mounting means positioned above said float member andmounting said float member so as to be self-supporting on said surface,said mounting means including vertical slide means interconnecting saidmounting means and said float member so as to permit self-adjustingvertical movement of said float member as determined by the contour andgrade of said surface while controlling horizontal movements of saidmember, said vertical slide means including vertically extending sliderod means and guide sleeve means slidingly receiving said rod means, oneof said sleeve and rod means being connected to said float member andthe other being connected to said mounting means, said mounting meansincluding horizontally slidable means mounting said vertical slide meansfor horizontal reciprocation in a direction lengthwise of said floatmember, float-reciprocating means carried by said mounting means forreciprocating said horizontally slidable means and thus said verticalslide means and said float member generally horizontally, and meanssuspending said mounting means from said carriage whereby travel of saidcarriage on said frame moves said float member across the concretesurface during reciprocating and self-adjusting vertical movement ofsaid float member.
 2. Apparatus according to claim 1 wherein said floatmember comprises an elongate flat straight member having leading andtrailing edges as determined by the direction of travel of saidcarriage, said reciprocating means reciprocates said member lengthwIse,said means suspending said mounting means including means mounting saidmounting means for pivoting movement about a horizontal axis of saidmounting means extending lengthwise of said float member, and verticallymovable means on said carriage and pivotally connected to said mountingmeans at a position offset from said horizontal axis for tilting saidmounting means and thus said float member about said axis so as tochange the height relationship between said leading and trailing edges.3. Apparatus according to claim 1 including winch on said carriage meansfor raising said float member from the concrete surface and for loweringsaid float member into contact with said surface.
 4. Apparatus accordingto claim 1 including vertically movable means on said carriage andconnected to said mounting means for tilting said mounting means andsaid float member about an axis extending generally parallel to aleading edge of said float member and winch means on said carriage forlifting said float member from the surface of said concrete. 5.Apparatus according to claim 1 including skewing means for varying theangular orientation of said float member with respect to said concretesurface in a generally horizontal plane whereby said float member can bemoved across said surface while skewed with respect to the direction oftravel of said carriage, said skewing means including turntable means onsaid carriage shiftable about a vertical axis, said means suspendingsaid mounting means being connected to said turntable means wherebyshifting of said turntable effects a skewing of said mounting means andthus said float member.
 6. Apparatus according to claim 1 wherein saidcarriage included an operator''s platform, motor means carried by saidplatform, pulley wheel means driven by said motor means, and pulleycable means for moving said carriage along said frame, and control meansmounted on said platform for controlling the operation of said motormeans and thus said carriage.
 7. Apparatus according to claim 6 whereinsaid float member includes an elongate, straight member having a broadflat bottom surface, lifting means on said carriage and connected tosaid float member for lifting said float member from the concretesurface, tilt means on said carriage and connected to said mountingmeans for varying the angular relationship of the bottom surface of saidfloat member to the concrete surface to be finished, and tilt and liftcontrol means accessible from said platform for controlling said liftingmeans and said tilting means.
 8. An apparatus for smoothing a concretesurface comprising: an overhead frame structure for spanning the widthof the concrete surface to be smoothed and supported on wheeled legs atits opposite ends for travel lengthwise of said surface, a carriagemovable on said overhead frame structure across said surface, anelongate float member for smoothing the concrete surface, andfloat-mounting means depending from said carriage mounting said floatmember for self-adjusting vertical movement as determined by variationsin grade and contour of said surface and for horizontal reciprocatingmovement lengthwise of said float member, said float-mounting meansincluding a horizontally reciprocative member slidable lengthwise ofsaid float member, vertical guide sleeve means carried by saidreciprocative member, and slide rod means extending vertically from saidfloat member and slidable within said guide sleeve means.
 9. Apparatusaccording to claim 8 wherein said legs supporting said frame structureare extensible for adjusting the height of said frame structure abovethe surface to be smoothed.
 10. Apparatus according to claim 8 includingpower means drivingly connected to at least one of said wheeled legs fordriving said frame structure lengthwise of said surface.
 11. Apparatusaccording to claim 8 including means for adjusting the position of saidlegs along the length of said frame structuRe for varying the effectivelength of said frame structure to accommodate varying widths of concretesurfaces and to enable the skewing of said overhead frame structure withrespect to the direction of travel of said structure.
 12. Apparatusaccording to claim 1 wherein said slide means permitting verticalself-adjustment of said float member includes an upright sleeve membercarried by a horizontally reciprocative portion of said mounting meansand an upright slide member extending upwardly from said float memberand slidable within said sleeve member.
 13. Apparatus according to claim1 wherein said means for reciprocating said float member included ahorizontal guide member, said horizontally slidable means being mountedfor sliding movement along said guide member, said horizontally slidablemeans pivotally mounting said guide sleeve means, said slide rod meansbeing pivotally connected to said float member and slidable within saidvertical guide sleeve means, motor means carried by said mounting means,and float drive means drivingly connected to said horizontally slidablemeans and said motor means for reciprocating said horizontally slidablemeans back and forth on said guide member.
 14. Apparatus according toclaim 8 wherein said carriage comprises: a wheeled base movable on saidframe structure, a turntable supported on said base for turning movementabout a vertical central axis relative to said base, and an operatorplatform supported by said base and restrained against turning movementrelative to said base, and hanger means extending downwardly from saidturntable supporting said float-mounting means.